Theory on nutrient ratios and algae/bacteria

[chefjpaul]

So, basically there ARE "ratios" regarding uptake of nutrients from these organisms we speak of, but they are more fluctuating, depending upon the system availabilities, export, uptake from dominating organisms etc??

 

[spiraling]

So, basically there ARE "ratios" regarding uptake of nutrients from these organisms we speak of, but they are more fluctuating, depending upon the system availabilities, export, uptake from dominating organisms etc??

My assumption is that every organism uptakes P and N, probably in different quantities, and maybe even different quantities over their lifetime. Having a wide variety of organisms helps prevent just one species from being dominant. So in a live rock system where you have hundreds of more organisms (or more) than a dry rock system, you are more likely to reach a stasis with the creatures sooner. Or at least you may not have dinos and cyano so heavily.

Its exactly this uptake in unknown amounts, along with trace elements we may or may not measure for, that is the je ne sais quoi of reefing - why one tank is more "sucessful" than another although the setup may seem identical.

 

[spiraling]

During night time they was migrating down to the bottom (if the bottom layer was anaerobic) and picked up phosphorous that they use in the sunlight during the day.

wow - thanks @Lasse for this post. I never thought of the bacteria in our tanks as being either deliberately mobile or able to move to feed. It really changes the way you think of the organisms in the tank and the different habitats there.

 

[mcarroll]

And let's blow some minds here and possibly off topic , I actually think with a lot of Dino's in apperanly nutrient limited tank systems the organizims are feeding in something else.

That's more than just a good theory – dino's really are feeding on something else (other that dissoved nutriets)!

As if that individual cellular-level feat isn't "enough", on the bloom-scale they are bio-engineering our tanks too.

It's all in Dinoflagellates – Are You Tired Of Battling Altogether?, man – the reason it was started. It will take this thread completely off track to go there in gory detail here too.

If you'd prefer an alternative, maybe have a look back at 2005's Dinoflagellates - Predators, Pathogens, and Partners by Eric Borneman. It's definitely better-presented but also highly compatible with the info you'll find my thread. @Dana Riddle may even find some useful info in there as Eric gets into action spectra of dino's.

And FYI no my thread not about simplistic ratio's or a simplistic focus on nutrients or any other "miracle cure"-like thing we can imagine like ozone, UV or antibiotics. It's about ecology – so it's about all of those things and quite a bit more.

In fact it's unfortunate that we're all still talking about "dino's" – maybe the greatest oversimplification in the whole discussion.

Dino's are a group of >2000 species which are almost exclusively harmless and even beneficial. Only around 5 groups/species cause all the problem blooms we see in aqariums and it's neither hard nor expensive to figure out which one(s) you're dealing with. So when a bloom is serious we try hard get folks to spend $10 on a microscope that can help them get a positive ID.

At minimum we get them to confirm they have dino's and not something altogether different.

 

[MnFish1]

My assumption is that every organism uptakes P and N, probably in different quantities, and maybe even different quantities over their lifetime. Having a wide variety of organisms helps prevent just one species from being dominant. So in a live rock system where you have hundreds of more organisms (or more) than a dry rock system, you are more likely to reach a stasis with the creatures sooner. Or at least you may not have dinos and cyano so heavily.

Its exactly this uptake in unknown amounts, along with trace elements we may or may not measure for, that is the je ne sais quoi of reefing - why one tank is more "sucessful" than another although the setup may seem identical.

I keep wanting to believe this thing about live vs dry rock - but knowing the doubling time of most bacteria - Im just not sure how this is supposed to work - put 1 or 2 corals in a tank - and shortly you will have a full set. I can see battles occurring between the different types - but having read this - multiple papers - and also @mcarroll 's excellent Dino thread - I am coming to the conclusion that its mostly about competition. If you have a lot of coral in a tank - there is less space for dinos, etc - and they compete for nutrients as well. If you have a bunch of dead rocks with a couple frags in a brightly lit tank you will have problems with algae/etc. If you have a bunch of live rocks alone in a tank with a bright light and nothing else - you may also have problems with algae/nusiance stuff. Seems to me its the proper balance of fish/food/coral/rock/other nutrients/supplements/2 part and some export method - that is the key - the bacterial microbiome will fight it out amongst itself over time.

 

[dave57]

I feel like our systems are so complex and the only thing that is of most value is our keen eye to the changes of our inhabitants. Everyone here will have different experiences whether good or bad. As far as my tank I’ve noticed it consumes so much N/P I’m dosing daily kno3 and close to 0.4 ppm of phosphates daily. Couple hours later all my nutrients are gone.. no biopellet reactor,carbon dosing, just a fuge, skimmer, no water changes for about 5 months already. I do get occasional cyano, Dino, gha.. i think it’s normal just like the pimples we occasionally get from time to time. It’s like trying to explain why some patients are more sensitive to certain medications than others... we don’t know.. but we must adapt and become aware of these sensitivities..

 

[Lasse]

I keep wanting to believe this thing about live vs dry rock - but knowing the doubling time of most bacteria - Im just not sure how this is supposed to work - put 1 or 2 corals in a tank - and shortly you will have a full set. I can see battles occurring between the different types - but having read this - multiple papers - and also @mcarroll 's excellent Dino thread - I am coming to the conclusion that its mostly about competition. If you have a lot of coral in a tank - there is less space for dinos, etc - and they compete for nutrients as well. If you have a bunch of dead rocks with a couple frags in a brightly lit tank you will have problems with algae/etc. If you have a bunch of live rocks alone in a tank with a bright light and nothing else - you may also have problems with algae/nusiance stuff. Seems to me its the proper balance of fish/food/coral/rock/other nutrients/supplements/2 part and some export method - that is the key - the bacterial microbiome will fight it out amongst itself over time.

I think your right - it’s about competition. It’s about diversity.

With live rocks - different bacteria already has populate the surfaces. That’s true for dry rocks also but there is probably a difference between the two populations – some bacteria, like the nitrification bacteria, is the same but the most is not the same. When you start the system with washed equipment, new clean sand and new clean rocks – it can become whatever. If you have some living rocks or some dirty gravel – the situation is different. Not any should start an aquarium without a handful of dirty gravel IMO.

When I start an aquarium from scratch – I always try to establish a bacterial population as soon as possible. It includes (if possible) used water with nutrients – if not possible – I add both NO3 and phosphate in one or another form. I always cycle with one fish – no other methods give me the control I need.

When a bacterial population are established – it will be very difficult to change that. I I´m not a hardcore believer of probiotics if you haven´t kill off the established population (or at least is weakened) it before. A change of the environment (nutrient levels, trace compounds, water temperature, light regime and/or inhabitants and other things) can together with probiotics make change – but I am not a believer of solely adding probiotics.

Look at your hand. The skin is covered with friendly bacteria – every mm of it. If an evil bacterium comes across – it has no chance. It will be like a full seated buss – hi/she will be kicked out. However, if you kill all your benefice bacteria on your hands – it’s like empty bus and the evil ones can be established.



Sincerely Lasse

 

[Brew12]

There is no reference for this. How is 'non-harmful bacteria' defined?

I very much dislike this term. While I don't know what the official definition is, it is a widely used term in scientific papers. I was shocked by the number of articles that divided bacteria into "harmful" and "non harmful" categories.
What I have figured out is that cyanobacteria can fit into both categories depending on the species. I've tried to find an exact definition with no luck.

Most bacteria increase with carbon dosing. Im not sure that you can assume that because 'non-harmful' bacteria have an N/P ratio of 50:1 implies that one needs a phosphate reducer. Thats not to say that people that dose carbon don't need a phosphate reducer - just that it has no relation to the N/P ratio or the bacteria.

As in the article I just posted - different cyanobacteria - there are LOTS of them - grow at different nitrate levels (high and low) - so how does adding nitrate help? How does the ratio imply that adding PO4 will help? (in this instance the ratio you quote is a factor of 500% different). I do not think you can use the ratio of the C/N/P in the organisms to suggest that this gives cyanobacteria an ability to thrive in a low nitrate environment.

As in the article I just posted - different cyanobacteria - there are LOTS of them - grow at different nitrate levels (high and low) - so how does adding nitrate help?

I'm going to focus on what I perceive as the two main concerns I see with these comments. The first is why I listed the N: P ratios that I did. I found multiple studies that investigated the C:N: P ratio of different marine organisms. These were fairly consistent in that they did not focus on single strains of any particular bacteria/flagellate/algae but looked at them as naturally occurring groups which are also averaged over time. So, as in the Redfield Ratio, they may not reflect an accurate picture at any single moment. As I believe I commented on earlier, the Redfield Ratio actually varies from 5:1 when dark and up to 35:1 under very bright lighting. Some individual strains of the phytoplankton become more efficient processing during the dark but most become less efficient.
As a side note, we see this changing of consumption in our aquariums being reflected in our NO3/PO4 testing. This is one of the main reasons it is important to test at the same time every day to be able to accurately determine trends.

If you are interested, I can try to dig up some of these articles and repost them. I do wish I had done a better job collecting the documentation I looked at. Note to self: well past time to start creating an offline library for these articles!


The other thing I have seen you express concern with is the basis for my recommendations. I will try to explain them in a broad manner which I believe will put them all into perspective.

Phytoplankton is the main driver of nutrient balance at the lowest level of the food chain and tends to carries its way up throughout. I also went to look at the N: P ratio of manufactured foods when it was available such as pellets and flakes. I found that most strive to keep the N: P ratio between 15:1 and 30:1. I did find one pellet manufacture that advertised a ratio of 5:1. I was disappointed that I couldn't find a ratio for any products advertised as "low phosphate". This research also reinforced that the ratio of food added falls in this range.
http://www.int-res.com/articles/meps/8/m008p015.pdf

My thought process is that if we understand the "average" N: P ratio of what we add we have an average N: P ratio of what is growing then we have a starting ground to make assumptions on possible treatments. With Carbon dosing we expect to be taking out 50:1 on average. Much of this is removed via skimming so is no longer available in the system. If we start with a ratio of 15:1 for nutrients added I feel it is reasonable to expect the balance of nutrients in our system would shift to one of higher phosphorus.

 

[Brew12]

As if that individual cellular-level feat isn't "enough", on the bloom-scale they are bio-engineering our tanks too.

It's all in Dinoflagellates – Are You Tired Of Battling Altogether?, man – the reason it was started. It will take this thread completely off track to go there in gory detail here too.

Dino's are a group of >2000 species which are almost exclusively harmless and even beneficial. Only around 5 groups/species cause all the problem blooms we see in aqariums and it's neither hard nor expensive to figure out which one(s) you're dealing with. So when a bloom is serious we try hard get folks to spend $10 on a microscope that can help them get a positive ID.

What you have put together in this Dino thread is really great stuff. Dino's are amazing life forms that come in a wide variety.

I would consider this thread to be a step back from that one. I am only attempting to address it from a very simplified "look for the easy and obvious stuff". I feel that looking at it from a nutrient perspective will either work or fail within 4 days. Beyond that, it is necessary to identify the specific strain (or at least more broad classification) to tailor a treatment path.

That's more than just a good theory – dino's really are feeding on something else (other that dissoved nutriets)!

Did you know that Marine Velvet is a dinoflagellate? They feed on fish!

 

[MnFish1]

I very much dislike this term. While I don't know what the official definition is, it is a widely used term in scientific papers. I was shocked by the number of articles that divided bacteria into "harmful" and "non harmful" categories.
What I have figured out is that cyanobacteria can fit into both categories depending on the species. I've tried to find an exact definition with no luck.





I'm going to focus on what I perceive as the two main concerns I see with these comments. The first is why I listed the N: P ratios that I did. I found multiple studies that investigated the C:N: P ratio of different marine organisms. These were fairly consistent in that they did not focus on single strains of any particular bacteria/flagellate/algae but looked at them as naturally occurring groups which are also averaged over time. So, as in the Redfield Ratio, they may not reflect an accurate picture at any single moment. As I believe I commented on earlier, the Redfield Ratio actually varies from 5:1 when dark and up to 35:1 under very bright lighting. Some individual strains of the phytoplankton become more efficient processing during the dark but most become less efficient.
As a side note, we see this changing of consumption in our aquariums being reflected in our NO3/PO4 testing. This is one of the main reasons it is important to test at the same time every day to be able to accurately determine trends.

If you are interested, I can try to dig up some of these articles and repost them. I do wish I had done a better job collecting the documentation I looked at. Note to self: well past time to start creating an offline library for these articles!


The other thing I have seen you express concern with is the basis for my recommendations. I will try to explain them in a broad manner which I believe will put them all into perspective.

Phytoplankton is the main driver of nutrient balance at the lowest level of the food chain and tends to carries its way up throughout. I also went to look at the N: P ratio of manufactured foods when it was available such as pellets and flakes. I found that most strive to keep the N: P ratio between 15:1 and 30:1. I did find one pellet manufacture that advertised a ratio of 5:1. I was disappointed that I couldn't find a ratio for any products advertised as "low phosphate". This research also reinforced that the ratio of food added falls in this range.
http://www.int-res.com/articles/meps/8/m008p015.pdf

My thought process is that if we understand the "average" N: P ratio of what we add we have an average N: P ratio of what is growing then we have a starting ground to make assumptions on possible treatments. With Carbon dosing we expect to be taking out 50:1 on average. Much of this is removed via skimming so is no longer available in the system. If we start with a ratio of 15:1 for nutrients added I feel it is reasonable to expect the balance of nutrients in our system would shift to one of higher phosphorus.

Thanks for clarifying your rationale. Again it’s inportant to know which n/p ratio you are talking about. Like when you say with carbon dosing we’re taking out 50:1 on average. There is no way to know this. With regard to skinming

When you say if we know the n/p of what we add I don’t understand what you mean. Do mean supplements in the water or the food.

Thanks for the detailed answer

 

[Brew12]

I keep wanting to believe this thing about live vs dry rock - but knowing the doubling time of most bacteria - Im just not sure how this is supposed to work - put 1 or 2 corals in a tank - and shortly you will have a full set.

I agree with almost everything in this post but want to throw up a caution with this one. I'm not saying I completely disagree, only that the process may not be as quick as implied.

It is true that many bacteria can reproduce very quickly unless they are limited by something. Reproduction of many bacteria in our systems are Carbon limited. This is why we can add a carbon source and quickly generate a bloom. The beneficial bacteria that would come in a larger population on a live rock may be carbon limited in its ability to reproduce when it is fighting for carbon availability with the other bacteria in our systems.

Nitrifying bacteria tend to be slower reproducers and double in population every 12 to 24 hours so some are a little slower to reproduce. Fortunately, these bacteria are rarely carbon limited since most can get 100% of their carbon needs via CO2.

 

[saltyfilmfolks]

Still no proof there is a measurable benifit of keeping a proper N/p "balance " or ratio in a tank.
Only reinforcement that limitation should be avoided.

 

[spiraling]

I´m convinced that lack of NO3 and somehow lack of PO4 in the water column is one of the things causing cyanobacteria bloom in our aquariums. I´m also lending to that it is so even for the Dino problems. Sometimes – you can have outbreak in high nutrient system but for the cyanobacteria part - I´m convinced there is a lack of micronutrients like iron in these cases.

So if we are agreeing that competition for available resources are the driving factor for what thrives in the aquarium, then how did the Swedish explain the lakes with higher NO3, so presumably more resource, had less cyano? Are you suggesting they coincidentally ran out of another resource?
not an argument, just a question to understand the logic.

 

[Brew12]

Still no proof there is a measurable benifit of keeping a proper N/p "balance " or ratio in a tank.
Only reinforcement that limitation should be avoided.

I have stated several times that keeping a specific ratio isn't important. I have also stated that it is impossible for a hobbyist to know the N: P ratio in their systems since it is much more complex than NO3/PO4. So not only is there no proof but it would be impossible to even recommend.

I feel it is useful to understand the N: P ratio of organism uptake which can be applied to help identify when a limitation has been reached along with what the limited resource may be.

 

[Brew12]

Thanks for clarifying your rationale. Again it’s inportant to know which n/p ratio you are talking about. Like when you say with carbon dosing we’re taking out 50:1 on average. There is no way to know this. With regard to skinming

I'll have to see if I can dig out the study I found that isolated the "non harmful" carbon limited bacteria to determine the 50:1 N: P ratio.
Did you want me to show a study with how these bacteria are absorbed by coral/algae or removed by skimmers?

When you say if we know the n/p of what we add I don’t understand what you mean. Do mean supplements in the water or the food.

It is the N: P ratio of the food we add to the tanks, not water supplements.

 

[spiraling]

It is the N: P ratio of the food we add to the tanks, not water supplements.

Many people dose N/P water supplements to make sure there is enough (more than 0). That's an interesting part of the discussion. By doing these elements are we allowing cyano and dino to more readily compete? Or is it better to leave one or both levels low? Or is it better to feed more and not dose supplements because the bioavailablity isn't what we think?

 

[saltyfilmfolks]

I feel it is useful to understand the N: P ratio of organism uptake which can be applied to help identify when a limitation has been reached along with what the limited resource may be.

Cool. Fair enough.
I do think is a bit of overthinking . But to each their own.

Many people dose N/P water supplements to make sure there is enough (more than 0). That's an interesting part of the discussion. By doing these elements are we allowing cyano and dino to more readily compete? Or is it better to leave one or both levels low? Or is it better to feed more and not dose supplements because the bioavailablity isn't what we think?

imo either works. Just a means to and end. It's the reefers comfort and method. Scientifically the same thing.

 

[Brew12]

Many people dose N/P water supplements to make sure there is enough (more than 0). That's an interesting part of the discussion. By doing these elements are we allowing cyano and dino to more readily compete? Or is it better to leave one or both levels low? Or is it better to feed more and not dose supplements because the bioavailablity isn't what we think?

I feel there is no need to dose nutrients or increase feeding unless it is in response to a symptom in the tank. It could be coral health, growth rate, cyano, dino's or any number of other issues.

Sometimes, feeding more may be the right answer, especially if you are talking about coral health. If cyano is a problem and you have no detectable NO3, I would add that. If you have dino's and no detectable PO4 I would add that. If you have cyano and no PO4 I would NOT add PO4. If I had dino's and cyano at the same time, or if I had cyano and yet had detectable NO3 then I would start looking at trace elements like iron and manganese.

 

[saltyfilmfolks]

I encourage feeding the fish healthfully. Keep up on water changes.
If you get cyano. It's usually not n/p.
In a system this complex , and an organizim this complex, n/p are way to poor an indication of causality.

 

[Brew12]

If you get cyano. It's usually not n/p.
In a system this complex , and an organizim this complex, n/p are way to poor an indication of causality.

This is where we disagree. If nitrogen and phosphorus weren't causing cyano/dino blooms we wouldn't worry about fertilizer run off so much.